Buggy texture when viewed at an angle

The block destruction animation is very bright when viewed at an angle,
as the pictures show.

What I expected to happen was...:
Normal, dark block breaking overlay.

What actually happened was...:
The overlay was really bright when viewed at an angle.

Steps to Reproduce:
1. Place a block (grass in this case).
2. Position the viewport in such a way, that you just barely see the side of the block.
3. Start breaking the block.
4. Observe the change in the section you can barely see.